Yes, they are affected by Intelligence and Combat Abilities, just like spells that you have learned.
Damage of an offensive spell scroll is affected by both Intelligence and rank in corresponding school (Aero, Hydro, etc). On the other hand, amount of Magic Armor restored by Armor of Frost is only affected by Hydrosophist rank, just like the standard spell. Physical Armor restored by Fortify is only affected by Geomancer rank.
An easy way to check it is to select different characters then hover the cursor over a scroll. You will see the difference reflected in the tooltip.
Last edited by Try2Handing; 11/08/18 02:30 AM.